Collaborative Research: CMG: Magnetohydrodynamics (MHD) Turbulence and the Geo-Dynamo: Lagrangian Averaging and Direct Numerical Simulations (DNS)

合作研究：CMG：磁流体动力学 (MHD) 湍流和地球发电机：拉格朗日平均和直接数值模拟 (DNS)

• 批准号: 0327533
• 负责人: David Montgomery
• 金额: $ 10.47万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0327533&HistoricalAwards=false
• 关键词: Collaborative; Research; CMG; Magnetohydrodynamics; MHD

Magnetic fields are a conspicuous feature of the ionospheres and magnetospheres of planets, including Earth, though their origin (the dynamo problem) is not well understood. This project is a theoretical investigation of magnetohydrodynamic (MHD) turbulence, or turbulent flow in the presence of magnetic fields. High resolution numerical simulations will be employed, and will be used to evaluate a method of simplifying turbulence processes called the Lagrangian-averaged (or "alpha") model. When validated, the method will be applied to MHD regimes relevant to the geodynamo (so-called low magnetic Prandtl number regimes) that have not been modeled previously. The work will not only advance the understanding of the geodynamo but will be a test of the alpha model, which has been proposed for other investigations of turbulent flow. The project provides for training graduate students and a postdoctoral research associate, and will sponsor an international workshop at NCAR on the modeling of complex geophysical flows in the summer of 2006. The grant is funded jointly by the Division of Atmospheric Sciences and the Division of Mathematical Sciences through the NSF program, Collaborations in Mathematical Geosciences (CMG).

磁场是包括地球在内的电离层和磁层的显着特征，尽管它们的起源（发电机问题）尚不清楚。 该项目是对磁场存在的磁性水力动力学（MHD）湍流或湍流的理论研究。 将使用高分辨率数值模拟，并将用于评估一种简化称为Lagrangian平均（或“ Alpha”）模型的湍流过程的方法。 经过验证后，该方法将应用于与Geodynamo（所谓的低磁性PrandTL数字制度）相关的MHD状态，该模式以前尚未建模。 这项工作不仅将提高对地毛的理解，而且将是对alpha模型的测试，该模型已被提出，用于对湍流进行其他研究。 该项目提供了培训研究生和博士后研究助理，并将在2006年夏季赞助NCAR的国际研讨会，以在2006年夏季对复杂的地球物理流进行建模。该赠款是由大气科学和数学科学司共同资助的。